1. Field of the Invention
The invention relates to a bait for marine animals. Accordingly, the present invention relates to an artificial bait for marine animals, comprising cell-free hemolymph of the horseshoe crab. Further, the invention relates to a method of preparing the same, and a method of attracting marine animals.
2. Related Art
Horseshoe crabs (Limulus polyphemus, Tachypleus tridentatus, T. gigas and Carcinoscorpius rolundicada) have traditionally been used as bait for eels (Anguilla rostrata) and conch, whelk (Busycon carica and B. canaliculatum) as well as other fin fish and shellfish. Unfortunately, over fishing for bait use has seriously depleted the horseshoe crab populations in the last few years, both in Asia (Tachypleus and Carcinoscorpius species) and in the United States. In the United States, the situation is especially critical in the center of the range of the horseshoe crab, namely the Delaware and Chesapeake Bay regions. In 1990 it was estimated that there was a spawning population of 1,200,000 crabs in the Delaware Estuary. In 1995, according to an annual census in which volunteers count the number of spawners coming ashore during a peak, one day period, there were fewer than 200,000. The Atlantic States Marine Fisheries Commission (ASMFC) is currently formulating a Management Plan because of the concern about over fishing.
The eggs of the horseshoe crab provide critical food for migratory shorebirds. As a consequence from the over fishing of the horseshoe crabs, the number of migratory shorebirds, for example, on New Jersey""s Delaware bay shoreline has declined precipitously since 1986, perhaps as much as 60%.
Further, the horseshoe crab is essential for the production of a critical biological reagent, Limulus Amebocyte Lysate (LAL) which is used worldwide as a pyrogen test for parenteral drugs, biological products, and medical devices. The use of LAL has been deemed critical by the United States Food and Drug Administration as well as other governmental agencies worldwide for the safety of pharmaceuticals.
The manufacture of LAL does not, however, result in the killing of horseshoe crabs. The crabs are bled under carefully controlled conditions and are returned alive to the ocean where they were collected. Unfortunately, the use of horseshoe crabs as bait has also threatened the LAL industry.
Applicants have developed an artificial bait for marine animals which attracts the game better than the horseshoe crab and does not involve killing the crab.
Applicants have discovered that the byproduct from the manufacture of LAL, the cell-free hemolymph of the horseshoe crab, is an excellent attractant to be used in artificial baits for marine animals. In fact, the baits containing cell-free hemolymph of the horseshoe crab attract the target marine animals better than the horseshoe crab itself. Further, the baits of the invention seem to attract non-target game less than the target game. Accordingly, the invention provides an artificial bait comprising cell-free hemolymph of the horseshoe crab.
The invention also provides a method of preparing an artificial bait for marine animals. The method comprises incorporating or enclosing a functionally effective amount of cell-free hemolymph of a horseshoe crab in a material or container capable of releasing the cell-free hemolymph when immersed in a marine environment. Another method comprises mixing a functionally effective amount of cell-free hemolymph of a horseshoe crab with a solid binder capable of releasing the cell-free hemolymph when immersed in a marine environment. A further method comprises absorbing a functionally effective amount of cell-free hemolymph of a horseshoe crab in a solid carrier capable of releasing the cell-free hemolymph when immersed in a marine environment.
The invention also provides a method of attracting marine animals wherein said method comprises connecting a bait containing cell-free hemolymph of the horseshoe crab as an attractant to a trap for marine animals and immersing the trap in a marine environment, whereby a functionally effective amount of the cell-free hemolymph is released into the marine environment.
It should be noted that a trap is intended to include all potential ways of catching marine animals. Thus, a trap can be, for example, a trot line, a weir, a wire cage, or a hook.
Additional embodiments and advantages of the invention will be set forth in part in the description as follows, and in part will be obvious from the description, or may be learned by practice of the invention. The embodiments and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.